No, he got a job really close by to the school and still hangs out at the club once in awhile. He’s actually still a major character. Actually, now that I think about it, in the same way Anakin Skywalker became the center of the six Star Wars movies despite not being a protagonist in most of them, Madarame has become the center of both of the manga series.

I wouldn’t consider Ryuuji Takasu from Toradora! a beta. He was polite and considerate but was not a push-over (except when it involved Tiaga). Now Oyamada Kouta from Kanokon (anime), he was the king of the betas.